Step bunching in chemical vapor deposition of 6H– and 4H–SiC on vicinal SiC(0001) faces

Step bunching and terrace widening on 6H– and 4H–SiC epilayers on vicinal {0001} faces have been studied with atomic force microscopy (AFM) and transmission electron microscopy (TEM). Macroscopically, hill-and-valley structures are observed on off-oriented (0001)Si faces, whereas surfaces are rather flat on off-oriented (0001̄)C faces. High-resolution TEM analysis revealed that 3 bilayer-height steps are dominant on 6H–SiC and 4 bilayer-height steps on 4H–SiC. The distribution of step height and terrace width are also investigated.